The ocean is vast and mysterious. There's so much scientists are still learning about life under the sea and they're discovering new things every year.

Joe Scott of Answers With Joe recently shared a video where he explores deep-sea sound recordings throughout history, many with a mysterious origin.

Photo: Pexels/Emiliano Arano

Among the deep-sea recordings that Joe talks about is a famous sound dubbed "the bloop."

According to the National Oceanic and Atmospheric Administration, researchers were listening for underwater volcanic activity in the southern Pacific back in 1997 when they recorded a "strange, powerful, and extremely loud sound." That sound, the loudest underwater sound ever recorded, later became known as the bloob, and it puzzled scientists for years.

Photo: YouTube/Joe Scott

Joe shared in his video, "The ocean is wide, vast, and terrifying. But for the last 40 years, researchers around the world have been recording audio from hydrophones to try to understand it better. And we've learned a lot. But a surprising number of sounds have been recorded that defy explanation. Here are some of the most mysterious."

In the video, Joe explains the various theories and speculation used over the years to explain the bloop. Some theories included the noise coming from an underwater military drill or an unknown sea creature, while more far-fetched theories speculated the noise came from aliens or mythical creatures.

Photo: YouTube/Joe Scott

While people are still speculating about what the mysterious loud noise may be, scientists actually cracked the code back in 2005. According to the NOAA, scientists discovered that the noise came from an iceberg cracking and breaking away from an Antarctic glacier.

An icequake may not be as exciting as a mysterious underwater creature or alien, but it's still neat to hear.

You can see Joe's video for yourself below: